Piston for internal combustion motors



Oct. 15, 1935'. E. c. LONG 2,017,630

PISTON FOR INTERNAL COMBUSTION MOTORS Filed Sept. 24, 1924 WWA Patented 0a. 15, 1935 Umrso STATES.

'ATENT .FFicE ris'roa For: manner. conmus'rron- Morons Elmcr 0. Long, Detroit, Mich.

Application September 24, 1924, Serial No. 739,522

11 Claims.

This invention relates to an improvement in pistons and particularly pertains to that class been forced on the cylinder wall between the 7 piston and the cylinder well.

Another object of the invention is in providing the skirt of a piston with an insert of metal which is to bear against the cylinder wall of a motor, said metal insert being made of a material difierent than the piston skirt.

A further object of the invention is in providing an aluminum alloy piston skirt with a metal cylinder bearing insert which is peculiarly formed so as to expand or contract with the material of the skirt portion.

A still further object of the invention is in providing means which are arranged interiorly of the skirt of the piston which act towards preventing the piston skirt from expanding outwardly under heated conditions in the cylinder in which the piston is reciprocated.

Other and fin'ther objects will appear in the specification and be specifically pointed out in the appended claims, reference being had to the accompanying drawing, exemplifying the invention and in which:

Figure 1 is an elevation of the thrust side of the piston.

Figure 2 is an elevation of the pin bearing side of the piston.

Figure 3 is a vertical section taken approximately on the line IIIIII of Fig. 2.

Figure 4 is a vertical section taken approximately on the line IV-IV of Fig. 1.

FigLn-e 5 is a transverse section taken approximately on the line V-V of 3.

Figure 6 is a fragmentary vertical section taken on the line VI-VI of Fig. 1.

With reference to the accompanying drawing this improved piston is provided with a closed end portion or head I ,having a packing ring supporting wall 2 in which a series of packing ring recesses 8 are provided. 7

'Depended from the closed end portion 8 or the piston by webs 5 are a pair of wrist pin bearings 5 and extending from each bearing is a vertically ed webbing 6 which is formed integral withtheskirt'l of the piston.

' l isseparated from the'wall 2 of the solid end portion I of the piston by a gap 8 and the wrist pin bearings 5 are each directly disconnected from the skirt although they are indirectly connected thereto by the webbing portions 6, said webbing portions 6 being tied to one 5 another by the pair of cross members 9, which are preferably located intermediate the extremities of the webbing portions and serve as fulcrums for controlling the direction of movements of the ends and central portions of the webbingm 6 as the piston expands and contracts'during temperature variations.

The skirt 7 is peculiarly slotted on each pin bearing side of the piston by a lo'ng it extending slot l0, whereas on the thriist sides 15 t of the piston a longitudinally. extending slot ii is provided, said slots [0 and H extending from the open end I? of the piston to the gap 8.

This separating of the skirt I of the piston by the longitudinally extending slots l0 and II proa0 vides a resilient skirt structure of four curved guiding slippers designated as 13, each of which is flexibly supported by respective portions of the webbings s.

A pair of vertically disposed'metallic inserts 95 ii are inlaid in each slipper I3, said inserts each being comprised of a body of cast iron and'are molded in the skirt during the casting of the piston, said metal inserts being provided with beveled edges such as it for thoroughly securing each of the inserts within the slippers l3 or skirt i.

Each oi the metal inserts it is provided with a series of transversely disposedslots it which extend from one side of each metallic insert .to a distance from the opposite side of the insert thereby providing a zig-zag shape within each insert as clearly shown in Figs. 1 and 2.

On account ofthe difference in the consistency of the metal of a piston of this improved character which is at the present day made from aluminum alloy, and the cylinder in which the piston is to reciprocate being made of cast iron, it has been found that an aluminum alloy piston will scufl or scour itself and the cylinder wall of the motor especially when the piston is reciprocating in a cylinder which is not properly lubricated. This improper lubrication is quite often brought about by permitting a motor to be 7 stopped for a considerable length of time especially in cold weather when the motor oil will congeal and become hardened and will not become thin until the motor has been put into operation long enough to warm thecongealed oil by friction and heat. 7

In the operation of a piston bearing the metal inserts Hintheskirtlinacomparativelydry cylinder, on accoimt of the inserts being of cast iron and therefore of the same consistency as is the cylinder wall, said inserts on account of being of harder material than the material or the skirt I will engage the cylinder wall during the reciprocation of the piston thereby preventing the aluminum material skirt from becoming active on the cylinder wall towards scumng as the cast iron inserts will receive the wear.

For permitting the metal inserts M to travel with the expanding material of each of the slippers l3, the transverse slots it of each insert will provide flexibility thereto, the inserts on account of the manner in whichthey are-embedded in the slippers being adapted to movement with the expanding material of the slippers.

On account of the cross members 9 tying the extending ends ofthe resiliently yieldable webbings 6, said members 9 will prevent said extending ends of said webbings from being carried outwardly by the wrist pin bearings 5 when thermal expansion occurs in said bearings and the depending webs or legs} from which the bearings are supported from the head. In this connection each of the cross members 9 are purposely arranged apprommately centrally of the distance betwen the respective side edges ll of the wrist pin bearings 5 and the respective lines [8 as designating a certain point on a respective slipper l3, each of said cross members 9 at their ends providing a fulcrum designated at IS on which the extending ends 20 of the respective webbings 6 will swing and move inwardly towards each other when the bearings 5 tend to move outwardly from one another by thermal expansion of the head I, such swinging action of the ends 20 of the webbings 6 tending to move opposing pairs of slippers I 3 towards each other and the diameter of theskirt'I-of thepistonwillbeinasensereduced and prevented from seizing against the cylinder wall.

A piston of this character is preferably diecasted, and for assisting the die-casting operation. of this improved piston, the spacings or openings between the depending webs I are provided, said openings permitting the withdrawal of certain cores sidewise from the piston, after the piston has been cast in the die-casting mold.

WhatI claim is:

1. A piston having an aluminum alloy smrt containing a. casted metallic insert which is adapted to engage the cylinder in which the piston is reciprocated, said metallic insert being of a material different than the material of the smrt and weakened on a pair of opposing edges.

2. A piston havingits shrt portion divided into a plurality of cylinder bearing slippers, each of said slippers containing a slotted cylinder bearing metal insert.

3. A piston comprising ahead, a skirt having oppositely disposed pairs of cylinder bearing B tions which are separated from the head of the piston, means for supporting said cylinder hearing portions from the interior of the piston, and means co-operable with said supporting means for tending to draw each cylinder bearing por- 5 tion of veach pair of cylinder bearing portions towards each other when the piston is heated during operation.

4. A piston having a solid end portion and a skirt separated from said solid end portion by a non-conducting gap, said skirt being divided into a pair of opposing pairs of slippers, a pair of wrist pin bearings depended from said solid end portion, a web extended from each of said bearings for engagement with aslipper of each pair of 15 slippers, and a tying member extending from and between said webs adjacent each pair of slippers.

5. A piston having a head and a skirt, a pair of slippers on one side of the skirt, pin bosses depended from the head, a support from each pin boss to a respective slipper, and tying means secured to and disposed between said supports for preventing outward movement to the extending ends of said supports when the piston is under the influence of heat.

6. A piston having a head and a skirt, said skirt having a pair of separated cylinder engaging parts, pin bosses supported from the head, a support extended from each pin boss to a respective separated part, and means for tying said sup- 30 ports to each other for preventing outward movement of the extending ends of said supports when the piston is under the influence of heat.

7. A piston having a head and a cross-head structure connected thereto comprising diametrically opposite slippers, pin bosses supported from the head, spaced resilient means joining said bosses and slippers together, and tying means intermediately secured to the spaced joining means.

8. A piston having a skirt and a slotted cylinder bearing metal insert contained in the skirt.

9. A piston having a skirt and a transversely slotted cylinder bearing metal insert contained in the skirt.

10. A piston having a head and a skirt divided into sections, pin bosses depending from the head within the skirt, joining means extending from the bosses to-the skirt sections, and devices associated with the joining means and cooperable therewith to draw. said skirt sections towards each other when the piston structure expands under the influence oif'heat.

11. A piston comprising a head and a skirt divided into sections and separated from the head,

'pln bosses supported from the head, and webs extending from the pin bosses to the skirt sections, and means connecting said webs and cooperabie therewith to act upon the skirt sections to prevent v normal expansion of the skirt sections when the 0 structure is under the influence of heat.

ELMER c. LONG. 

